Wednesday, October 31, 2012

We were fortunate to have projects in three national parks on the west slope this year: Dinosaur N.M., Black Canyon N. P. and Mesa Verde N.P. In Dinosaur during our June trip we documented Erigeron wilkenii, E. nematophyllus, Oenothera acutissima, Oxytropis besseyi ssp. obnapiformis and several Pellaea glabella occurrences. In July, due to the low water in the Yampa River, we were able to wade (sometimes swim) across the river and access the north side, where we found some wonderful alcove seeps with Adiantum capillis-veneris, Anticlea vaginata, Limnorchis zothecina and Cirsium ownbeyi.

An alcove seep in Dinosaur National Monument.

It was so hot that every time we came back to the river from a foray up a canyon, we jumped right in.

CNHP botanist Peggy Lyon coolin' off in the Yampa.

In Black Canyon N.P. we established permanent monitoring protocols for Sullivantia hapemannii and Gilia penstemonoides. This year’s drought really affected two other targeted species, Astragalus anisus and Thelypodiopsis juniperorum. For the latter we found more dead plants from 2011 than living ones.

CNHP botanist Dee Malone in Black Canyon National Park.

In Mesa Verde Peggy with Park Service botanist Merran Owen found large new populations of Hackelia gracilenta, Astragalus deterior and Lepidium crenatum.

Botanist Peggy Lyon in front of ruins in the Mesa Verde National Park.

Wednesday, October 24, 2012

As Colorado scientists concentrate more on the potential effects of climate change, CNHP ecologists are wondering if there is any evidence that treeline is moving up into the previously treeless alpine zone. One limiting factor for the upper elevation treeline is summer temperatures. As summer temperatures increase we can expect to see trees colonizing the alpine zone. Approximately 3% of Colorado is currently considered the alpine zone. Documenting changes to this ecosystem is an important part of understanding the impacts to the native fauna and flora under changing climate.

CNHP’s Renée Rondeau recently used repeat photography to document a change in tree density over the past 40 years, at Montgomery Pass (near Cameron Pass) in Larimer County. The 1972 photos were taken in the Montgomery Pass area by Gordon Rodda. In September 2012, Renée, with volunteers Jennifer Kathol, Maureen DeCoursey and Anne Taylor took new photos from the same location. (click to see larger versions).

Looking down from the alpine to treeline. The hills in the distance are the slopes of Sawmill - the dramatic increase in tree density in that area is probably due to regrowth after logging in the early 1900s. The higher tree density in the mid-ground, where the circled area has filled in with trees, is not related to past logging. Many of the mature trees in 2012 appear dead, probably from spruce-bud worm or mountain pine beetle kill.

View of Clarks Peak. New trees have appeared at edge of treeline and subalpine tree density has increased.

Although the repeat photos do not indicate that that treeline has moved upslope in a systematic way, it appears that tree density in the subalpine and near treeline has increased. It is typical to see a few scattered trees growing some distance above the actual treeline. The increasing tree density at treeline may indicate an infill mechanism by which treeline moves upslope in incremental stages rather than as a solid advancing front. We don’t yet know if the observed changes are tied to warmer temperatures it is important to keep documenting these trends.

View of Nokhu. The bolting of wind stunted trees in the alpine (krummholz) could be another indicator of warming temperatures. In the righthand photo you can spot a couple of krummholz trees that have changed since 1972.

If you have any old (40 years or older) photographs of treeline areas in Colorado, and would be interested in sharing them with us, please contact Renée Rondeau.

Thursday, October 18, 2012

A few months ago, CNHP joined forces with botanists from the U.S. Fish and Wildlife Service and the Mosquito Range Natural Heritage Initiative to survey for rare plant in the Leadville area. The conditions were perfect. Despite a few threatening clouds, we had a bluebird survey day. After four hours of crawling through the alpine, we found what we were looking for. The tiny plant, Eutrema penlandii, is a member of the mustard family (Brassicaceae). Listed as Threatened under the Endangered Species Act, it is found primarily in wetlands and alpine fens above treeline.

Volunteer Merit Glenne at the new Eutrema penlandii site near Mt. Arkansas, outside Leadville, Colorado.

Very few populations of E. penlandii have been mapped on the west side of the Continental Divide. Our findings suggest more surveys on this side of the Divide may result in a range expansion for this narrowly distributed Colorado endemic.

Tuesday, October 16, 2012

Long-time CNHP botanist Peggy Lyon was honored at the 9th annual Rare Plant Symposium in late September. Peggy, who will be retiring in 2013, received a framed print of Mimulus eastwoodiae in recognition of her many years of service to Colorado's rare plants.

Peggy (center) receiving her award.

The meeting was attended by over 50 professional and amateur botanists from around Colorado.

Thursday, October 11, 2012

Long-term population sampling for the Preble’s meadow jumping mouse (PMJM) has allowed Rob Schorr to estimate population change (λ) for the population along Monument Creek at the U.S. Air Force Academy (Academy). Using mark-recapture techniques and a novel population model that allows estimation of survival and recruitment, Schorr estimated changes in PMJM λ from 2000-2006. Although λ varied annually, the 7-year mean showed a declining population, and λ was less impacted by changes in PMJM survival than by changes in PMJM recruitment.

Recruitment can be influenced by immigration or reproduction. Given the loss of habitat along eastern tributaries of Monument Creek, there are limited opportunities for increasing immigration from these tributaries and this may be a driving force during this time. However, Schorr warns that this may be a temporary decline that will be compensated by increased reproduction or immigration from western tributaries that are on the Academy.

Tuesday, October 9, 2012

The Treasure Fire that burned approximately 400 acres just east of Leadville this past summer came within a half mile of the only known boreal toad breeding site in Lake County. The boreal toad is a state endangered species with a patchy distribution throughout the central mountains of Colorado. The Birdseye Gulch population is monitored by CNHP biologists who conduct yearly visits as part of a project funded by Colorado Parks and Wildlife.

Boreal toad

The fire started on June 24th and was headed up the gulch towards the breeding pond. Fortunately the fire changed directions and missed the breeding pond. The fire was contained by July 2nd. USFS biologist Jeni Windorski of the Leadville Ranger District was able to work with firefighters in protecting the breeding site. The toads were probably not impacted much as the riparian area was spared. CNHP resumed monitoring in August and documented the successful metamorphosis of the tadpoles in early September.

Tuesday, October 2, 2012

Join The Nature Conservancy, the Gunnison Climate Working Group, and other partners for the Gunnison Climate Adaptation Project Volunteer Days on Oct 13-14. Contact Betsy Neely (720-974-7015 or bneely@tnc.org) with questions.